There are a number of tools that can help you find keywords for your SEO campaign.
There are three major types of keyword research tools:
1. Free keyword research tools
2. Paid keyword research tools
3. Tools that combine both free and paid features
The first type is free, but they sometimes don't provide as much information as the other two types of tools and their results may be outdated. The second type is paid, but they offer more detailed data than the free ones and their results are always up to date.
The third type offers a mix of features from the first two types, which means they're more expensive than the second one but cheaper than the first one.
The website SEOWords.info provide a tool to analyse websites. And it is free !
I think it is made to get info on your website, but you can put any url in the box to get info on every website.